Means for refrigerating



June 12, 1945. F. R. BICHOWSKY MEANS FOR REFRIGERATING Filed June 20, 1940 2 J a s wwmw m f f H a Z 9 01w. A 2 i I 00 0 3 7 M 7 M M2 3 000000 000 E named June 12, 1945 UNITED STATES PATENT. OFFICE 2,378,177 I MEANS ma anmr sns'rmd. Francis R. Bichowsky, Ann Arbor, Mich. Application June 20, 1940,- Serial No. 341,572

11 Claims. (01. a Y

This invention relates to improved methods of refrigerating and apparatus therefor. More spepciflcally the invention is concerned with improved methods of refrigerating in apparatus of the vacuum absorption type. Refrigerants commonly employed are water, methyl alcohol, or the like and frequently used absorbents are solutions of lithium chloride, lithium bromide, zinc chloride,

' and similar salts.

It is among the objects of the present inven tion to provide vacuum absorption apparatus in;

--parts,'name1y, the evaporator I0 and the absorber 5. The evaporator includes trays II which are sloped slightly downward toward the center of the evaporator and placed in staggered formation; alternate trays being placed on opposing sides of the evaporator. A liquid primary refrigerant distributor I4 is placed in the top of the evaporator and a sloping plate -IB in the bottom To the accomplishment of the foregoing and related] ends, the invention, then consists of the.

methods and means hereinafter fully described and particularly pointed out. in the claims, the annexed drawing and'the following description setting forth in detail certain methods and means for carrying out the invention, such' disclosed methods and means illustrating, however, but severalof various ways in which the principle of the invention may be used.

In said annexed drawing: Figure 1 is a side elevation of a vacuum absorption refrigerator illustrating the principle of the present invention. Figure 2 is a plan view of the same apparatus drains into the absorber sump l8; Pipes l2 are attached to the bottom of the trays ll so that materialscirculating in said pipes are in heat exchange relation with said trays.

The absorber 5 includes finned coils Q and aliquid absorbent distributor 1, said liquid absorb-.

chamber 32 containing a centrifugal pump 28 driven by a motor 3| taken on the line 22. Figure 3 is an isometric 1 mounted on a furnace for air conditioning.

In Figure 1, an hermetically sealed vessel I is "pmvided in the form of a box. This vessel contains a high pressure chamber 2, a low pressure chamber 6 and has a leg 28 appended to it. The two chamberaare separated from the vessel I by a space 9, said space communicating 'withthe low pressure chamber 8 by an opening 4 in the wall 6f said chamber.

The high-pressure chamber 2 is divided into two parts, namely. a condenser and a; regenerator 36. The condenser includes coils 38 through which a cooling agent may be run. The

finned coils a. The finned coils It contain a In the preferred embodiment of this invention the primary refrigerant enters the evaporator section In by means of the distributor M. The refrigerant flows over thejtrays H, the major methane, whereby the secondary refrigerant is circulated in an air-cooling chamber. The vapor' of the primary refrigerant is passed from th e evaporator into the absorber through the open V collects in the sump". This sump communi- V regenerator 26 includes finned coils 38 and a liquid cates with the pump chamber 32 by means of an opening 19. Absorbent may thus flow from the sump to the bottom of the pump chamber and thereby enter the'pump 28 by an' opening, not shown, and leave through the pipe 20. The major' portion of the diluted-absorbent coming out of the pump 28 is returned by the pipe 3 to the distributor l in the top of the absorber 5 and is redistributed over the coils l. The remainder of the absorbent leaving the pump 28 through the pipe 20 flows through the pipe 2! cooling coils 33 in the condenser cool the vapor.

so that it is condensed. Because of the relatively high temperature of the liquids in the chamber 2, the pressure in this portion of the apparatus will be substantially higher than that in the chamber 6. Thus the condensate in the condenser section 35 passes into the pipe 29 and into the sump 25 contained in the leg 26. A pipe 21 connects the sumps 25 and 24 above the liquid level therein with the condenser chamber 35 so that pressure may be communicated from the condenser chamber to the sumps. Then, since the pressure in the sump 25 is higher than that in the chamber 6, the water flows by means of the partially-finned pipe 23 through the evaporator ID to the distributor 14 therein to be passed again through the system.

The concentrated absorbent after passing over the regenerator coils 33, 39 passes over the hereinbefore-mentioned heat interchanger coils 30, thereby being partially cooled, and thence into the pipe 4| and down to the sump 24 from whence it is forced by the higher pressure therein to the absorber sump It by means of the pipe 22. From there it ispassed into the absorber 5 .by means of the pump 28 and other apparatus hereinbefore described.

Since considerable heat is generated in the absorber by the absorption of water vapor in the absorbent, the coils 8 which are utilized to spread the absorbent also contain a liquid cooling agent to absorb and carry this heat away.

It has been found that there is a tendency for warm water entering anevacuated space to flash into spray. There .is a tendency for this spray to be carried along by the water vapor produced and thus have its refrigerating effect lost. In order to prevent this flashing, the tube [5 for conveying primary refrigerant to the distributor 14 in the evaporator I0 passes through-the evaporator and is in thermal contact with the interior thereof so that the liquid flowing through the herein is provided with an opening 4 in the absorber through which theinert gas is forced into the space 9.

In Figure 2 the flow of secondary refrigerant and cooling water is more particularly shown. The secondary refrigerant is recirculated in the coil I3. Cooling water passes through the coils 8 and then through the coils 38 and hence either to waste or to the hot water supply of the house by means of the pipe 52. A by-pass 42 with valve 43 is provided to send a portion ofthe cooling water around the condenser when desired. A valve 44 is provided to control the flow of cooling water to the absorber.

It has been found that the amount of heat removed by the cooling water leaving the condenser is proportional to the heat removed by the cooling water from the absorber and that, therefore, by setting the amount of water by-passed around the condenser so that the pressure difference between the absorber and condenser is at a predetermined value, that pressure difference will maintain itself regardless of the load, if the inlet water temperature is approximately constant. A pressurestat or thermostat 41 may be provided to control by means of the valve 44 and the connecting means 48 the flow of cooling water through the absorber coils 8 (as shown in applicants copending application Serial No. 286,989. filed July 28, 1939, which has now matured into U. S. Patent No. 2,298,924)

Figure 3 shows the apparatus mounted on top of an ordinary hot water or steam furnace. An air conditioning unit 45 is also mounted on top of the furnace.

While the mode of operation of the specific apparatus illustrated has been described, my.

method broadly comprises recirculating a sec-- ondary refrigerant in heat exchange relation with an evaporating primary refrigerant; passing said evaporating primary refrigerant from heat exchange relation with said secondary retube I5 is pre-cooled before entering the distributor 14. To further this effect, the liquid entering the evaporator I0 is passed through progressively wider passages, the ones at the top being narrow relativeto the lower ones. Thus, the vapor is restricted in its flow through the evaporator and the pressure at the distributor I4 is greater than that at any other point in the evaporator and flashing is limited to a minimum.

Since the temperatures obtained with pure water are limited by the freezing point thereof. (32

1".) if lower temperatures should be desired while using water as the primaryrefrigerant, a trough 31 may be provided in the regenerator 36 so that a small proportion of the absorbent therein flows into the condenser section 35,'joins the condensed water and thus gives a primary refrigerant solutlon flowing back to the evaporator I 0 with a freezing point lower than that of water,

It has been found that complete exhaustion of frigerant into an absorbing medium; passing the so-formed mixture of primary refrigerant and absorbing medium into a pump and returning the major portion of said mixture to the absorption zone for re-use as absorbing medium, passing the minor portion of said mixture to a heating zone, passing the vapor thereby obtained into a condensing zone and returning the so-formed condensate to the zone wherein primary refrigerant is evaporated, said condensate being in heat exchange relation with primary refrigerant evaporating in said zone before being passed thereinto; and passing that portion of the mixture not vaporized in the heating zone back to the absorption zone for re-use as absorbing medium.

Other modes of utilising the refrigeration obtained can be used besides the secondary refrigerant circuit without exceeding the scope of the present invention.

Qthermodes of applying the principle of this invention may be employed instead ofthose exequivalent is employed. What is claimed is: 1. Vacuum absorption refrigeration apparatus comprising a container within a surrounding'airtight wall, said container being divided into two chambers, one of said chambers including an evaporator and an absorber, and one of said chambers including-a regenerator and a condenser; means providing communication between.

the absorber-evaporator chamber interior and the space existing between the wall and the container.

2.' Vacuum absorption refrigeration apparatus including a regenerator, a condenser, an absorber, and an evaporator, means for passing liquid from said regenerator including a sump located below said regenerator, means for equalizing pressure between said sump and said condenser, and apipe connecting saidsump below the liquid level in said sump with said absorber.

3. Vacuum absorption refrigeration apparatusincluding a condenser and an evaporator, means for conveying liquid from. said condenserto said evaporator including a sump located below said evaporator, means for equalizing the pressure in said sump with that in said condenser, and communicating means between said sump and said. condenser.

5. .Vacuum absorption refrigeration apparatus including anevaporator, an absorber, a regenerator and a condenser, means for cooling said condenser and absorber whereby the condenser and absorber are cooled by a single liquid passed cooling liquid passed from the absorber is bypassed around the condenser.

6. Vacuum absorption refrigerating apparatus including an evaporator, an'absorbe'r, a regeneratorand a condenser means for utilizing the refrigeration produced in said apparatus to cool a secondary refrigerant, means responsive to the a temperature of said secondary refrigerant to control a new of cooling agent to the absorber and condenser.

7. Vacuum absorption refrigeration apparatus comprising a container divided into two chamhers, one of said chambers including an evapora- 2,378,177 stated by any of the following claims or their refrigerant leaves said passage.

in series, and means whereby a portion of the tor and an absorben-and oneof said chambers including a regenerator and a-vcondenser, said evaporator including a passage through which, primary refrigerant may pass, said passage being narrower at the point at which primary refrigerant enters than the point at which primary 8. Vacuum absorption refrigeration here, one of said chambers including an evaporator and m absorber, and one of said chambers including a regenerator and a condenser, and means for conveying primary refrigerant into the evaporator including a tube in thermal contact with the interior of said evaporator.

9. Vacuum absorption refrigeration apparatus comprising a container divided into twochambers. one of said chambers including an evaporator and an absorber, and one of said chambers including a regenerator and a condensensaid evaporator including a passage through which primary refrigerant may pass. said passage being narrower at the point at which primary refrigerant enters than the point at which primary refrigerant leaves said passage, heat exchange means in said evaporator for cooling a secondary refrigerant, means responsiveto the temperature of said secondary refrigerant to control the flow of cooling agent to the said condenser and absorber, and means for conveying primary refrigerant into the evaporator including a tube in-thermal contact with the interior of said evaporator. 10. Vacuum absorption refrigeration apparatus comprising an absorber and an evaporator, said evaporator comprising a chamber and a series of downwardl sloping taggered trays positioned therein to define a passageway for primary refrigerant; said passageway starting between the topmost tray and thetop wall of said chamber and being progressively larger to its point of discharge short of the bottom of saidchamber. means for introducing primary refrigerant ad- Jacent the small end of said passageway and means for transferringvaporlzed primary re-,

frigerant from said chamber below said-passageway to the absorber.

11. Vacuum absorption refrigeration apparatus comprising a container divided into two chambers, one of said chambers forming an evaporator and an absorber and the other of said chambers forming a regeneratorand a condenser, means for'circulating a primary refrigerant between said two chambers, means for circulating a secondary refrigerant in a circuit partly inside and partly outside of said container, and

means responsive to the temperature of said seei ondary refrigerant controlling a; flow ofcooling" 7 agent to the absorber and condenser.

. FRANCIS R. 'BICHOWBKY.

apparatus 4 comprising a container divided into two cham- 

